*4.3. Defuzzification*

The fuzzy inference rules give linguistic variables that need to be transformed into crisp values. Therefore, the defuzzification process is implemented to quantify the output of the fuzzy logic. To do so, there are different methods of defuzzification. In this article, the weighted average method is implemented. The defuzzified slope rate (i.e., 1/*Rt*) is defined as:

$$output = \frac{\sum\_{i=1}^{m} Z\_i \* \mu(Z\_i)}{\sum\_{i}^{m} \mu(Z\_i)} \tag{4}$$

where *Zi* represents the center of the defined function, and μ(*Zi*) is the value of the membership that corresponds to *Zi*. Then, the output (1/*Rt*) of the fuzzy-logic controller is used to gives the rate of the droop in Equation (3).
